Food release coating

ABSTRACT

Coating composition for applying grease resistant, non-sticking coatings to sheets of cellulosic material and the resultant products which are suitable for use in storing, displaying and cooking food products, the coating composition comprising at least one thickener or film forming material, a Werner type chromium complex and water.

United States Patent [191 Gallino Feb. 19, 1974 1 FOOD RELEASE COATING[75] Inventor: Robert Gallino, Englewood Cliffs,

[73] Assignee: Lowe Paper Company, Ridgefield, NJ. I

[22] Filed: June 16, 1972 [21] App]. N0.: 263,506

Related US. Application Data [63] Continuation-impart of Ser. No.13,193, Feb. 20,

1970, abandoned.

[52] US. Cl 117/155 UA, 117/121, 117/161 UE [51] Int. Cl D211! 1/38 [58]Field of Search 117/155 UA, 161 UE, 121

[56] References Cited UNITED STATES PATENTS 2,273,040 2/1942 ller.117/100 X 2,356,161 8/1944 Iler 117/121 X 2,356,879 8/1944 Pense etal.... 117/142 2,999,768 9/1961 Boresch 117/121 3,484,271 12/1969Kaliski et a1. 117/62.1 3,558,676 l/l97l Doherty 117/162 X PrimaryExaminer-William D. Martin Assistant ExaminerM. R. Lusignan Attorney,Agent, or Firm-Albert C. Nolte, .lr.; Edward B. Hunter; C. Bruce Hamburg1 Claim, No Drawings 7 1 FOOD RELEASE COATING This is acontinuation-in-part of Ser. No. l3,l93, filed Feb. 20, 1970, nowabandoned.

In the use of brown and serve" packages by the food industry it is theconventional practice to remove the food from the original package,transfer the same to and to bake the same on a previously prepared usualmetal cookie tray or pan. This is also the case in connection with theconventional roll, cookie or biscuit baking carried out in the home oreven on a commercial scale. That is, the cookies, etc. are baked on alarge previously greased metal cookie tray.

It is an object of the invention to eliminate the necessity of usingmetal cookie or baking trays for the actual baking of the food andtherewith the associated disadvantages of storage, cleaning, rustprevention, etc.

In accordance with the invention, the bread, biscuits, cookies, buns,rolls, etc., can be cooked directly in the paper board package in whichthey have been stored and displayed under conventional conditions e.g.,25 minutes at 350375F. The storage, display and baking means areprepared in accordance with the invention by applying onto a sheet ofcellulosic material, for example, a paperboard substrate, a coatingcomposition consisting of a thickener or film forming material, a Wernertype chromium complex and water, using conventional coating techniques.The resultant product is then suitable for use both as the packagingmeans and as the cooking pan for the food. The same coating can beapplied onto paperboard where the resultant prodnets are intended foruse asdisposable cooking trays.

The coating of the invention serves to impart two distinct uniquequalities to the underlying cellulosic material and namely 1. greaseresistance; and

2. the ability to allow the food to be very easily released from thepaperboard without any necessity of greasing the pan prior to the bakingorcooking opera tron.

The coating is readily applied by all of the known conventional methods.It is normally applied out of a water based system and, therefore, noexpensive and often dangerous solvent recovery systems are required.

The coating composition in accordance with the invention comprises athickener or film forming material such as polyvinyl alcohol, a Wernertype chromium complex which is preferably a chrome-stearato complex, forexample, Quilon (DuPont), and water.

The components can be readily mixed in proper proportions for obtainingthe results above mentioned.

In order to achieve the desired food release function of the coating,the chrome complex must constitute at least about 2 percent by weight ofthe coating formulation. A coating viscosity of no less than about cps.,measured in Brookfield units at 72F. at 10 rpm, must be maintained togive proper coating spread. For this purpose a conventional thickener orfilm former, such as polyvinyl alcohol, carboxymethyl-cellulose, sodiumalginate, starches and the like, may be included in the formulation.Such a thickener or film former as polyvinyl alcohol serves theadditional function of imparting additional grease resistance to thecoating.

It is of great importance that the cellulosic substrate not be so porousas to be over-absorbent. Such an overabsorbent substrate will allowexcessive drainage of the food release coating, whereupon insufficientcoating will remain on the surface to provide proper release.Accordingly, a minimum Cobb Size Specification of about 0.30 g. waterabsorbed must be maintained. This may be done by any of the knownmethods in the art, such as application of size either added in thefurnish or onto the surface, application of a base coat, glazing,supercalendering, or similar finishing operations. On

7 the other hand, surfaces non-wettable by water, such as attained bytreating with materials such as wax, untreated polyolefins or waterrepellent chemicals, which cannot be coated with formulations of theinvention by normal coating methods, are to be avoided.

Conventional coating or sizing application can be carried out before theapplication of coating of the invention by conventional procedures, suchas application of two coats in one pass, or pre-sizing and coating inone pass, or beater sizing and coating on a paper machine, or the like.

- An example of a grease resistant ready release coating in accordancewith the invention is the following:

Polyvinyl alcohol 6 wt.% aqueous solution I00 gallons stearato chromecomplex 33 wt.% isopropyl alcohol solution 9 gallons water 25 gallons.

Application air knife coate'r Paperboard 0.024 inch coated bleachedsulphate Weight Coat Application 3.0 gals/3000 sq. ft.

While the invention has been described by reference to preferredembodiments, it is intended that all embodiments within the spirit ofthe invention be included within the scope of the claims.

What is claimed is:

l. Coated paperboard having grease resistant and non-sticking propertiescomprising a sheet of paperboard having a minimum Cobb SizeSpecification of about 0.30 g. water absorbed coated with a mixtureconsisting essentially of polyvinyl alcohol thickener and a sufficientproportion of Werner type chromium complex to impart said properties tothe coated paperboard.

